1. Field of the Invention
The present invention relates to an image taking apparatus such as a digital camera, a mobile phone with a camera and the like using a light emitting diode as a flash light source of a flash device.
2. Background Arts
Photographic film cameras, digital cameras, mobile phones with cameras and the like are known as image taking apparatuses. Many of the image taking apparatuses are equipped with flash devices so as to illuminate main subjects for taking beautiful pictures in low luminance conditions.
Xenon (Xe) tubes have been used as flash light sources in the conventional flash devices. However, as for the digital camera, a flash device using a light emitting diode (an LED) is recently suggested in terms of low noise, easy downsizing, and low cost.
For instance, an image taking apparatus with plural LEDs is known which can adjust the color balance of the flash light by sequentially emitting each LED at predetermined intervals or by adjusting light emitting time of each of the red, green and blue LEDs (see Japanese Patent Laid-Open Publication No. 2001-215579). Further, a mobile phone with a camera using a white LED as a flash emitter is known (see Japanese Patent Laid-Open publication No. 2003-158675) A slim-type digital camera and a mobile phone-with a camera in which plural LEDs are disposed around taking lenses on front surfaces of the bodies are known (see Japanese Patent Laid-Open Application Publication No.2003-101836). A flash device is known which uses red, green and blue LEDs as the flash light source and a ratio of respective light emission amounts is controlled according to the color temperature of the view field (see U.S. Patent Publication No. 2002/0025157).
The LEDs described above have a disadvantage that the light emission amount is small compared to the conventional xenon tubes. To achieve a sufficient light emission amount, a high voltage current should be supplied to the LEDs. However, the LEDs may be destroyed by the high heating value.